Fireproof material



Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE FIREPROOF MATERIAL NoDrawing. Application November 6, 1933, Serial No. 696,923. In GermanyNovember 22,

3 Claims.

This invention relates to improvements in fireproofing of normallyinflammable fibers of animal and vegetable origin; more particularly itrelates to materials which are rendered fireproof 6 by a. treatment witha mixture of an uninfiammable wax and an uninfiammable lacquer-formingcompound, and to a process of preparing such fireproof materials.

While no inflammable materials of organic 10 origin can be made whollyincombustible since all such materials will decompose and char whenheated sufficiently, yet they can be made flameproof or flame-resisting,i. e. so that the flame does not spread when the impregnated material isheated for some time and that the flame will extinguish in a short time.This is the commercial sense of the word fireproof and is the oneemployed herein.

For fireproofing fibers by means of suitable uninfiammable wax-likecompounds, such as chlorinated naphthalene or chlorinated diphenyl, thefibers must be pretreated with certain inorganic salts, such asdiammonium phosphate and sodium sulfate. This manner of working istroublesome for it necessitates several working steps. The fibersareimpregnated in aqueous solution with the inorganic salts, then theyare thoroughly dried, thereafter they are impregnated with the wax-likechlorinated hydrocarbon. It has also been proposed to impregnate thefibers with a. highly chlorinated naphthalene containing 68% ofchlorine. The coating and impregnation made from this highly chlorinatednaphthalene becomes however brittle and fissured on account of thecrystalline structure of the chlorinated naphthalene containing 68% ofchlorine, the coatings therefore do not adhere firmly.

In accordance with the present invention these difliculties are overcomeby impregnating the fibers, such as wool, cotton, silk, paper, wood andmaterials made therefrom with a. mixture of can be added, or 15% ofcolophony, or 30% of residues from tar distillation without the mix turebecoming inflammable. As uninfiammable lacquer-forming compoundsespecially chlorinated rubber containing about 50 to 73% chlorine andpolyvinylchloride come into consideration. To. the uninfiammablelacquer-forming compounds plastifiers and stabilizers may be added inthe usual small amounts. The proportion of mixture of the compounds ofthe two groups changes according to the materials employed, in mostcases a small addition of the uninfiammable lacquer-forming compoundsuffices to obtain the desired results. For instance, a mixture of aboutto 95 parts by Weight of the wax-like uninfiammable compound with 5 to30 parts by weight of the lacquer-forming compound yields excellentresults in fireproofing. By this manner of working the fibrous compoundis not only fireproofed but it becomes also water-proof.

The invention is further illustrated by the following examples but it isnot restricted thereto:

Example 1.--A copper wire covered with dry cotton or silk cross wound ona bobbin is immersed into a molten mixture having a temperature of to C.consisting of 95 parts by weight of a chlorinated naphthalene with achlorine content of 50% and 5 parts by weight of chlorinated rubber witha chlorine content of 60%. As soon as the evolution of air bubbles hasceased the wire is rewound under intercalation of a wiper or stripper toremove the excess of the impregnating mixture. On a wire impregnated insuch a manner a flame does not spread.

Example 2.A fabric is immersed into a melt as used in Example 1. Afterit has been thoroughly impregnated it is passed .over a heated calenderor it is centrifuged to eliminate the adhering excess of impregnatingmaterial.

' Example 3.-A copper wire covered with paper and cross wound on abobbin is treated in the same maner as indicated in Example 1 in a meltconsisting of 90 parts by weight of a chlorinated naphthalene containing60% of chlorine, 1 part by weight of. ozocerite or paraflin oil orcolophony or a mixture of these additions and 10 parts by weight ofchlorinated rubber containing 73% of chlorine and 0.5 to 1 part byWeight of tricresylphosphate and 0.01 to 0.1 part by weight of phenoxypropenoxide as a stabilizer. Also .on this wire the flame extinguishesnear the ignition spot.

The terms wax-like chlorinated naphthalene and wax-like chlorinateddiphenyl used in the claims are intended to comprise wax-like, resinlikeand highly viscous chlorinated naphthalenes and diphenyls and suchmixtures of these compounds with other-waxes, resins and the like,

which are uninfiammable in the commercial sense of the word.

I claim:

1. An organic fibrous material impregnated with a mixture of 70 to 95parts of an uninflammable wax-like chlorinated naphthalene containingabout to 60% of chlorine and 30 to 5 parts of a chlorinated rubbercontaining about to 73% of chlorine, said material being fireproof andwaterproof.

2. An ,organic fibrous material impregnated with 90 parts by weight of achlorinated naphthalene containing of chlorine, 1 part by weightRU'DOLF' ENGELHARDT.

